| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic metal-halide lamp of high-wattage type capable of reliably preventing scattering of fragments of an arc tube in case of a burst of the arc tube. SOLUTION: In the ceramic metal-halide lamp 1, the periphery of a main tube portion 11 of the arc tube 10 is covered with a silica cylinder 20 whose length is equal to or greater than 1.1 times that of the main tube portion 11, and the distance from the outer surface of a maximum diameter portion of the main tube portion 11 to the inner surface of the silica cylinder 20 is set to 4 mm or greater. Furthermore, one-half or greater part of the outer peripheral surface of the silica cylinder 20 is covered with a metallic mesh material 21 of 4 mesh or finer. Such a configuration makes it possible that, even when the arc tube 10 has burst, fragments thereof are received by the silica cylinder 20 and the metallic mesh material 21 provided on the periphery of the main tube portion 11 with reliability, and breakage of an outer bulb portion 2 is thereby prevented with reliability. COPYRIGHT: (C)2008,JPO&INPIT
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